SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Dec 07, 2012, 05:39 PM
Registered User
Joined May 2008
26 Posts
Discussion
RC Flying Christmas Tree

Hi guys.

anyone know how to find out (Easily!), the C of G of a Flying Christmas Tree?
Basically just a delta, set up with Elevons, but I'd rather it didn't plummet groundwards on its maiden flight.
is there an easy idiot proof way of figuring out where the C of G should be on a scratch built delta?
I've seen plenty of youtube videos of these flying, but none go into any detail about the C of G!
It's built, and power system is up and running (front mounted prop), but I've held off placing the battery, until I have some idea of where it needs to go!

Any help would be great!

Thanks in advance.

Andy
andrew_1967 is offline Find More Posts by andrew_1967
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 07, 2012, 05:42 PM
Registered User
jetcommander's Avatar
Joined Jan 2012
285 Posts
This one might do the job and you can save an image of the worked out data, in the window at the top put 15% CG for beginners and play safe. Donīt forget the lights on the tree.

http://wingcgcalc.bruder.com.br/en_US/?
jetcommander is offline Find More Posts by jetcommander
Reply With Quote
Old Dec 07, 2012, 05:48 PM
Registered User
Joined May 2008
26 Posts
I'm not very bright!!!

looks like the sort of thing I'm after, but I've not got the first clue how to go about putting in the necessary data!!

I can do length and span at the widest point (Back!!) but that's about it!!
andrew_1967 is offline Find More Posts by andrew_1967
Reply With Quote
Old Dec 07, 2012, 07:57 PM
Wake up, feel pulse, be happy!
C₄H₁₀'s Avatar
United States, AK, Fairbanks
Joined Aug 2009
12,425 Posts
This calculator is a little simpler to use. It's pretty self-explanatory, too.
C₄H₁₀ is offline Find More Posts by C₄H₁₀
Reply With Quote
Old Dec 08, 2012, 05:46 AM
Registered User
Joined May 2008
26 Posts
thank you for this. I'll give it a go!!
andrew_1967 is offline Find More Posts by andrew_1967
Reply With Quote
Old Dec 11, 2012, 02:24 AM
Registered User
Joined May 2008
26 Posts
It flies!!!

Many thanks to those who helped!
The C of G calculation charts helped no end.
The first flight was a pretty un eventful experience, as the tree sprang into the air like a Saturn five rocket! Went straight up, and performed a right hand turn as intended, then flew around for a minute or two, with a heave back on the stick as it approached me on its finals, pointed skywards, to be caught gracefully.
A little tail weight was added to assist with high Alfa passes (in an attempt to make it look a little tree like) with the nose pointing almost straight up!
Open the taps and it'll fly around like any other delta mix!
Now to add paint and the all important lights!!
andrew_1967 is offline Find More Posts by andrew_1967
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Flying Christmas Tree sr71fan Foamies (Scratchbuilt) 64 Dec 20, 2012 10:06 AM
Discussion CG location needed for a Delta shape (Flying Christmas Tree) danford1 Electric Plane Talk 5 Dec 03, 2012 02:48 PM
Cool Rocket powered Christmas Tree noxnflame Rocketry 6 Oct 22, 2012 05:41 PM
Video 5888 Flying a "Christmas Tree" Shape & Spot Landing Heavy_D Electric Heli Talk 2 Jan 11, 2011 12:08 PM